Welt insole



Dec. 30, 1952 s, M G'RISWOLD 2,623,306

WELT INSOLE Filed Marh 17, 1949 Our-ing Resin fn Our-ea Condizz'onRubber Cemenz l La faz Cemen Cumamne-[ndene i Resin wm mr Patented Dec.30, 1952 WELT INSOLE Stanley M. Griswold, Newton, Mass., assigner to B.B. Chemical Co., Boston, Mass., a corporation of MassachusettsApplication March 17, 1949, Serial No. 81,938

2 Claims.

This invention relates to Welt insoles having stiffening and supportingmeans in their ribs.

Frequently, in this art, canvas is laid over a core piece to form a,rib, the core piece giving shape to the rib by supporting the fold ofcanvas laid over it. Objects of this invention are to provide asatisfactory material for use as a core piece. Laminated material suchas pasteboard or a board of ber impregnated with latex have been used.However, the pasteboard is too weak and the impregnated berboard is noteasily penetrated by the needle. In either case, the needle is apt to bedeflected so that it passes under the core piece, which is objectionablebecause it produces irregularities in the feather line of the shoe.Furthermore, the material previously used has had to be thick to providethe necessary strength, whereas it is desirable that the core piece bethin, the criterion being a thin, strong, penetrable and widthwiseiiexible strip.

In cementing canvas to the core piece with pressure-responsive cement,such as latex, a better bond to the stiffened core piece will beobtained if the core piece is nrst coated with rubber cement.

It has been found that a welting machine having its needle set foroperation on regular economy Work does not operate satisfactorily onshoes having insoles with ribs comprising the previously used corematerials and that a resetting of the needle is required. When the ribsof insoles comprise the core piece of the p-resent invention, no

resetting of the needle is required.

In the manufacture of insoles by the method described in Letters Patentof the United States No. 2,538,776, granted January 23, 1951, upon myapplication, the strip forming the core piece, during its introductioninto the fold of the canvas, is bent widthwise and pasteboard oriiberboard core pieces would not always stand this bending withoutdelaminating or breaking, Whereas the core piece of the presentinvention is especially adapted for use in that method. To meet theabove objections and to overcome these objections to prior materials,the present invention provides a core piece comprising a strip of fabricsuch as Gem duck which is so stiifened with a stiffening material as towithstand the widthwise strains to which it is subjected, a core piecestiffened with a curing resin, a core piece to which latex will adherewith a good bond, and a ycore piece which is thin and penetrable by theneedle Without tendency to strand that is, to catch on the barb of theneedle. In practice, the core piece is preferably united with a wider,less Stffened strip so that a marginal portion of the wider strip may beturned at right angles to the core piece and secured to the body portionof an insole to serve as an anchorage for the core piece and to assistin preventing deflection of the needle under the core piece. Thisconstruction also affords a better abutment for the channel guide andrafirmer rib to hold the inseam stitches.

These and other attributes and advantages of the invention will appearfrom the following description when read in connection with theaccompanying drawing and will be pointed 'out in the appended claims.

In the drawing- Fig. 1 represents a coil of the core piece mate rialstiffened with a curing resin; i

Fig. 2 represents a coil of a less stiifened, Wider reinforcing strip;

Fig. 3 is a cross-section of a core after the core piece and thereinforcing strip are united;

Fig. 4 is an enlarged diagrammatic crosssection of the core piece ofFig. 1, the legend indicating its successive treatments;

Fig. 5 is a view, similar to Fig. 4, of the wider reinforcing strip;

Fig. 6 is a diagrammatic View indicating the size and arrangement of thestrands in the core piece;

Fig. 'l is a fragmentary cross-section of an insole in which a corepiece With a reinforcing strip has been used, a strip of canvas havingbeen formed over it; and

' excess is scraped off and the material run through squeeze rolls tocause thorough penetration. The strip is then passed through an ovenwhere, after drying, it is subjected to a temperature of 300 F. forabout seconds. The material is next coated on one side only with rubbercement. This is done by bringing the material into contact with theupper portion of an applying roll which is dipping into thin rubbercement, the excess being scraped off. The material then passes through.

an oven heated by steam pipes to evaporate the rubber solvent. It hasbeen'found that a better bond of latex to the core piece i9 is obtainedif the strip is rst coated with rubber cement, though of course therubber cement coating may be omitted. Finally the material is coatedwith latex on the side previously `coated with rubber cement and allowedto dry. From the material thus treated core pieces I9 of indefinitelength and about one-fourth inch wide are made.

An anchoring and reinforcing strip i2 is preferably made of the samematerial (Gem duck) and is treated first with a 20% solution ofcoumarone-indene resin V, which may be that manufactured by the BarrettCompany, of 40 Rector Street, New York, N. Y. When dry, the strip l2 iscoated with latex on both sides. material thus treated is made intostrips l2 of indefinite length but nearly twice as wide as the corepieces i9. The core pieces i and reinforcing strip l2 are then united bypressure, one edge of the strip i9 being flush with the edge of thestripv 2-, as shown in Fig. 3, the latex-coated side of the core piecei9 being next to: the strip l2.

This composite strip may be used with a cemented strip of canvas i4 laidover it to form a. reinforced rib onv a body layer or insole E9, thesingle-ply portion of the strip being applied to the insole and thestrip i4 cemented over it, as indicated in Fig. 7.

The core piece i0 made in the manner describedv comprises warp threadsi9 extending lengthwise of it and ller threads 20 extending crosswise ofit. In Gem duck the ller threads 2U are larger than the Warp threads;.ior ei;- ample, there may be 72 Warp threads to the inch and 32 llerthreads to the inch. The filler threads; being larger and beingimpregnated With a curing resin as described, are able to withstandwidthwise pressure applied to the strip. Such strips, when tested byapplying pressure widthwise'to-them, have sustained very substantialpressures before buckling. rThis at-l tribute is particularly importantwhen such strips areY used in the manufacture of insoles by the methoddisclosed in the above-mentioned patent Where the core piece is forcedinto the fold of anali-over layer of canvas I4 (Fig. 7). A suitableinsole rib may be formed by utilizing the core piece I9 without thestrip l2, the core piece being enclosed in astrip of canvas 22 wideenough tof provide flanges for attaching it to an insole or body portionIE on each side of the rib, as shown in. Fig. 8.

While the Resinox 465 has been found satisfactory as a stiffeningmaterial for the rib,y other stfiel'lingVv material which Will producethe required eiect may be employed, though a curing resin: is believedto be preferable. Other curing resins than Resinox may be employedWhether the curing iseiiected by heat, as in the case of Resinox, or iseffected by a catalyst, by chemical means, or is naturallyself-hardening by a lapse of time. Other curing type aldehyde resinswhich may be usedv are the urea-formaldehyde resins and themelamine-formaldehyde resins. These resins may be cured by heat in thesame manner as Resinox, which is understood to be of thephenol-formaldehyde type.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent of the United States is:

1. A welt insole having a rib set inwardly from its edge, said insolecomprising an unchanneled body portion of insole size and shape, anall-over TheY ` 4 layer of canvas, said layer having a fold thereinforming in part said rib, said fold enclosing a stifened core piece ofGem duck having its filler threads extending heightwise of the rib, saidcore piece being impregnated with a curing type aldehyde resin to form athin, strong widthwise ilexible core piece readily penetrable by asewing needle having no tendency to strand and having high resistance topressure applied heightwise of the rib, said core piece being reinforcedby a less stiffened strip of Gem duck separate. from the core piece,said reinforcing strip being impregnated with coumarone-indene resin,said strip being twice as wide as the core piece,

' one-half of said strip being adhesively secured to said core piece andthe other half of the strip being cement-attached to the said bodyportion to prevent deflection of the needle under the core piece, saidall-over layer and said body portion being attached by cement alone toeach other inside of and outside oi the rib, and said all-over layerbeing cement-attached to said reinforcing strip inside of the rib.

2. A welt insole having a rib set inwardly from its edge, said insolecomprising an unchanneled body portion of insole size and shape, anall-over layer of canvas, said layer having a fold therein forming inpart said rib, said fold enclosing a stiffened core piece of Gem duckhaving its 'liler threads extending heightwise of the rib, said corepiece being impregnated with a curing type aldehyde resin and coatedWith latex cement to form a thin, strong widthwise flexible core piecereadily' penetrable by a sewing needle having no tendency to strand andhaving high resistance to pressure applied heightwise of the rib, saidcore piece being reinforced by a less stiffened strip of Gem duckseparate from the core piece, said reinforcing strip being impregnatedwith coumarone-indene resin and coated with latex cement, said stripbeing twice as wide as the core piece, one-half oi said strip beingadhesively secured to said core piece and the other half of `the stripbeing cement-attached to the said body portion to prevent deiiection orthe needle under the core piece, said allover layer and said bodyportion being attached by cement alone to each other inside of andoutside of the rib, and said all-over layer being cement-attached tosaid reinfor ing strip inside of the rib.

STANLEY M. GRISWOLD,

REFERENCES CITED The following references are of record in the le ofthis patent:

UNTED STATES PATENTS Number Name Date 1,298,156 Arlidge Mar. 25, 19191,352,739 Egerton Sept. 14, 1920 1,654,240 Davis Dec. 27, 1927 1,760,820Drew May 27, 1930 1,776,879 Baelreland Sept. 30, 1930 1,973,124 Swan etal. Sept. 1l, 1934 1,998,125 Eno Apr. 26, 1935 2,021,870 Reynolds Nov.19, 1935 2,106,385 Springer Jan. 25, 1938 2,128,653 Charch et al Aug.30, 1938 2,341,713 Griswold Feb. 15, 1944 2,427,739 Paulsen Sept. 23,1947 2,458,500 Bertrand et al. Jan. 11, 1949 Dillehay Mar. 22, 1949

